Perinatal outcomes for extremely preterm babies in relation to place of birth in England: the EPICure 2 study

Abstract

Background: Expertise and resources may be important determinants of outcome for extremely preterm babies. We evaluated the effect of place of birth and perinatal transfer on survival and neonatal morbidity within a prospective cohort of births between 22 and 26 weeks of gestation in England during 2006.

Methods: We studied the whole population of 2460 births where the fetus was alive at the admission of the mother to hospital for delivery. Outcomes to discharge were compared between level 3 (most intensive) and level 2 maternity services, with and without transfers, and by activity level of level 3 neonatal unit; ORs were adjusted for gestation at birth and birthweight for gestation (adjusted ORs (aOR)).

Findings: Of this national birth cohort, 56% were born in maternity services with level 3 and 34% with level 2 neonatal units; 10% were born in a setting without ongoing intensive care facilities (level 1). When compared with level 2 settings, risk of death in level 3 services was reduced (aOR 0.73 (95% CI 0.59 to 0.90)), but the proportion surviving without neonatal morbidity was similar (aOR 1.27 (0.93 to 1.74)). Analysis by intended hospital of birth confirmed reduced mortality in level 3 services. Following antenatal transfer into a level 3 setting, there were fewer intrapartum or labour ward deaths, and overall mortality was higher for those remaining in level 2 services (aOR 1.44 (1.09 to 1.90)). Among level 3 services, those with higher activity had fewer deaths overall (aOR 0.68 (0.52 to 0.89)).

Interpretation: Despite national policy, only 56% of births between 22 and 26 weeks of gestation occurred in maternity services with a level 3 neonatal facility. Survival was significantly enhanced following birth in level 3 services, particularly those with high activity; this was not at the cost of increased neonatal morbidity.

Keywords: Epidemiology; Neonatology.

Figure 1

Population of births reported to the EPICure 2 study by place of birth and transfer status, indicating the population of babies included in antenatal transfer, neonatal transfer and activity analyses.

Figure 2

Mortality by place of birth, perinatal transfer and high and medium activity level 3 services for babies born in England in 2006 at 26 completed weeks of gestation or less. GA, gestational age in weeks; BW, birthweight for gestation as ‘z’ score; L2/L3, level of service; ANT, antenatal transfer; NNT, neonatal transfer; CRIB, clinical risk index for babies II score⁹; ANS, any antenatal steroid given to mother.

Figure 3

Kaplan–Meier plots of survival by gestational week for babies born at 23–26 weeks of gestation in level 3 and level 2 centres in England in 2006. Antenatal deaths are plotted as t=1 and delivery room outcomes care as t=2, with admission to neonatal unit as t=3 and subsequently postnatal age in days to 40 weeks postmenstrual age.